Vehicle sound emission control

ABSTRACT

A speed of a target vehicle can be detected. A difference in host vehicle speed and the speed of the target vehicle is determined. A target frequency is specified for a sound to be received at the target vehicle. A sending frequency is determined for the sound based on the target frequency and the difference in host vehicle speed and target vehicle speed. The sound is transmitted at the sending frequency.

BACKGROUND

The Doppler effect describes the phenomenon whereby a wave emitted froma source at a given frequency will be received by an observer at adifferent frequency if the observer is moving relative to the source.Light and sound waves can experience the Doppler effect.

Anyone who has listened to the siren of a moving vehicle such as a trainblowing a horn or an emergency vehicle sounding a siren has experiencedthe Doppler effect. The sound of a vehicle moving toward you will have ahigher pitch than it would have if you and the vehicle were stationarywith respect to each other. The sound of a vehicle moving away from youwill have a lower pitch than it would have if you and the vehicle werestationary with respect to each other. This is because sound waves froma vehicle moving toward an observer are compressed, and sound waves froma vehicle moving away from an observer are expanded. Thus, the Dopplereffect can result in a sound such as a siren emitted from a vehiclesbeing perceived at different pitches or tones than would be perceivedwere the vehicle and an observer (i.e., perceiver) of the soundstationary with respect to each other. However, sounds perceived atcertain pitches may not be effective, e.g., can be difficult to hearand/or may not provide an intended warning.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an exemplary system for controlling sound emittedfrom a vehicle.

FIG. 2 is a diagram of an exemplary traffic scene.

FIG. 3 is a flow diagram of an exemplary process for controlling soundemitted from a vehicle.

FIG. 4 illustrates an exemplary process to determine a frequency orfrequencies, and to specify zones for respective frequencies to betransmitted, from a host vehicle.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, described herein is a system 100 wherein ahost vehicle 105 can adjust emitted sounds such as sirens to compensatefor the Doppler effect, i.e., to optimize emitted sounds for recipients.The host vehicle 105 includes sensors 120 that can provide data fromwhich the host vehicle 105 can detect one or more targets, i.e., objectto receive sound from the host vehicle 105, such as one or more targetvehicles 205 (i.e., vehicles other than the host vehicle 105) orpedestrians 215. Further, in addition to detecting its own speed, thehost vehicle 105 can detect speeds of identified target vehicles 205.The host vehicle 105 can determine its speed relative to a targetvehicle 205, and, to compensate for the Doppler effect, can adjust afrequency at which sound is emitted from the host vehicle 105, e.g., bya siren, so that that sound will be received at the target vehicle 205at a frequency whereby the sound will be heard at a desired, andpossibly unchanging, but possibly varying within a specified range,pitch, rather than at a pitch than changes and/or is higher or lowerthan a pitch or range of pitches at which the host vehicle 105 emittedsound is desired to be heard.

Referring now to FIG. 1, the system 100 in a host vehicle 105 includesthe host vehicle 105 and elements as described herein to control andadjust emission of sounds from vehicle 105 speakers 135. The vehicle 105is referred to as a “host” vehicle for convenience, i.e., to denote thatthe host vehicle 105 is a vehicle 105 emitting and adjusting sound asdisclosed herein. The host vehicle 105 and target vehicles 205 (FIG. 2)may be any suitable type of motorcycle, truck, van, etc. The vehicle105, for example, may be an autonomous or semi-autonomous vehicle 105.In other words, the vehicle 105 may be autonomously operated such thatthe vehicle 105 may be driven without constant attention from a driver,i.e., the vehicle 105 may be partly or entirely self-driving withouthuman input. Further, although the vehicles discussed herein are landvehicles, it will be understood that presently disclosed and claimedprinciples could be applicable to waterborne and/or airborne vehicles.

The host vehicle 105 includes a computer 110 that includes a processorand a memory such as are known. The memory includes one or more forms ofcomputer 110 readable media, and stores instructions executable by thevehicle 105 computer 110 for performing various operations, including asdisclosed herein. The computer 110 may include programming to operateone or more of vehicle 105 brakes, propulsion (e.g., control ofacceleration in the vehicle 105 by controlling one or more of aninternal combustion engine, electric motor, hybrid engine, etc.),steering, climate control, interior and/or exterior lights, etc., aswell as to determine whether and when the computer 110, as opposed to ahuman operator, is to control such operations. Additionally, thecomputer 110 may be programmed to determine whether and when a humanoperator is to control such operations.

The computer 110 may include or be communicatively coupled to, e.g., viaa vehicle 105 network such as a communications bus as described furtherbelow, more than one processor, e.g., included in components such assensors 120, electronic controller units (ECUs) or the like included inthe vehicle 105 for monitoring and/or controlling various vehicle 105components, e.g., a powertrain controller, a brake controller, asteering controller, etc. The computer 110 is generally arranged forcommunications on a vehicle 105 communication network that can include abus in the vehicle 105 such as a controller area network (CAN) or thelike, and/or other wired and/or wireless mechanisms. Via the vehicle 105network, the computer 110 may transmit messages to various devices inthe vehicle 105 and/or receive messages (e.g., CAN messages) from thevarious devices, e.g., sensors 120, an actuator, an HMI 115), etc.Alternatively or additionally, in cases where the computer 110 actuallycomprises a plurality of devices, the vehicle 105 communication networkmay be used for communications between devices represented as thecomputer 110 in this disclosure. Further, various controllers and/orsensors 120, including as described further below, may provide data tothe computer 110 via the vehicle 105 communication network.

The vehicle 105 can include an HMI 115 (human-machine interface), e.g.,one or more of a display, a touchscreen display, a microphone, a speaker135, etc. The user can provide input to devices such as the computer 110via the HMI 115. The HMI 115 can communicate with the computer 110 viathe vehicle 105 network, e.g., the HMI 115 can send a message includingthe user input provided via a touchscreen, microphone, a camera thatcaptures a gesture, etc., to the computer 110, and/or can displayoutput, e.g., via a screen, speaker 135, etc.

The host vehicle 105 can include various sensors 120. A sensor 120 is adevice that can obtain one or more measurements of one or more physicalphenomena. Often, but not necessarily, a sensor 120 includes adigital-to-analog converter to converted sensed analog data to a digitalsignal that can be provided to a digital computer 110, e.g., via anetwork. sensors 120 can include a variety of devices, and can bedisposed to sense and environment, provide data about a machine, etc.,in a variety of ways. For example, conventional sensors in the vehicle105 can include one or more radar sensors 120A, a vehicle speed sensor120B, as well as other sensors to provide data about a location, speed,environment, etc., of the vehicle 105, such as ultrasonic transducers,weight sensors, accelerometers, motion detectors, etc., i.e., sensors120 to provide a variety of data, etc. Moreover, various controllers ina vehicle 105 may operate as sensors 120 to provide data via the vehicle105 network or bus, e.g., data relating to vehicle 105 speed,acceleration, location, subsystem and/or component status, etc. Toprovide just a few non-limiting examples, sensor 120 data could includedata for determining a presence and/or location of an object around avehicle 105, a speed of an object, a type of an object (e.g., vehicle,person, rock, etc.), a slope of a roadway, a temperature, an presence oramount of moisture in an ambient environment, etc.

The computer 110 can determine or detect a speed of a target vehicle 205via data from various sensors 120, e.g., as described herein, a radarsensor 120A is used in some examples. A radar sensor 120A as is knownuses radio waves to determine the relative location, angle, and/orvelocity of an object. Further, the computer 110 could identify as atarget vehicle 205 an object detected by sensors 120, e.g., a radarsensor 120A, as moving not only with respect to the vehicle 105, butwith respect to a ground surface. Yet further, the computer 110 couldidentify a target vehicle 205 or other target such as a pedestrian 115,and/or determine a speed or speeds thereof, by techniques forinterpreting sensor 120 data such as lidar data, video or still cameraimage data, upon which a suitable object recognition technique, forexample, could be performed to identify the target 205, 215, etc.

The host vehicle 105 computer 110 can detect a speed of the host vehicle105 via data from a host vehicle speed sensor 120B. A vehicle speedsensor 120B outputs a vehicle 105 speed, i.e., a rate of movement of thevehicle 105, typically in a forward direction, with respect to a groundsurface such as a road 210. For example, one or more wheel speed sensors120 can be provided as is known to detect a rate of rotation of vehicle105 wheels, from which a speed of the vehicle 105 can be determined.Alternatively or additionally, a vehicle speed sensor 120B can detect arate of rotation of a crankshaft, from which the vehicle 105 speed canbe determined.

As further discussed below, the host vehicle 105 computer 110 candetermine a difference in the host vehicle 105 speed and the speed ofthe target vehicle 205. For example, a speed of a target such as atarget vehicle 205 can be determined via data from a radar sensor 120A.A vehicle 105 speed can be determined from a speed sensor 120B in thevehicle 105. A simple subtraction operation can then be performed todetermine a difference between these two speeds as discussed furtherbelow.

The host vehicle 105 computer 110 can specify a target frequency for asound to be emitted from speaker(s) 135 based at least in part on alocation of the target vehicle 205 relative to the host vehicle 105. Forexample, as discussed further below, and referring also to FIG. 2, thecomputer 110 can select one or more zones 220 wherein a location of atarget such as a target vehicle 205 or pedestrian 215 is within a zone220, to receive sound at a target frequency or frequencies.

Sound at the target frequency can be provided, i.e., emitted, byutilizing a frequency generator 130 coupled to a speaker 135. Thecomputer 110 can be programmed to actuate a first speaker 135 totransmit a first sound at the first sending frequency and a secondspeaker 135 to transmit a second sound at the second sending frequency.The computer 110 can be further programmed to actuate a speaker 135 at afirst time to transmit the first sound at the first sending frequencyand to actuate the speaker 135 at a second time to transmit the secondsound at a second sending frequency.

A frequency generator 130 includes programming and hardware to generatea wave, typically a sine wave or the like, at a specified frequency. Thefrequency generator 130 can vary the specified frequency of the outputwave over time, e.g., in a range between a specified lower boundaryfrequency and an upper boundary frequency, e.g., in the case of a soundwave, to create a siren effect. For example, a computer 110 could beprogrammed to output a digital waveform at the specified frequency, thefrequency generator 130 further including a digital-to-analog converterto convert the digital waveform into an analog signal to be input to aconventional amplifier (not shown) that can be included in a speaker 135or otherwise in the system 100. The host vehicle 105 computer 110 canfurther be programmed to specify a range of frequencies from a firstfrequency to a second frequency, and to transmit the sound within therange of frequencies.

A loudspeaker, or speaker 135, is a device that, as is known, canconvert an electrical signal to sound, i.e., a speaker 135 can include atransducer that converts the electric signal to vibrations to generatesound at a desired frequency. A speaker 135 can receive the electricalsignal from an audio amplifier.

As noted above, the host vehicle 105 computer 110 can detect more thanone target, including more than one vehicle 205. The host vehicle 105computer 110 can determine at least one second sending frequency for atleast one second sound, and can then transmit a second sound or soundsat a specified volume and/or in a specified zone 220 (see FIG. 2) to beperceived by a detected target such as a target vehicle 205 orpedestrian 215. The host vehicle 105 computer 110 can further beprogrammed to specify the frequency for the sound based at least in parton a path and/or or location of the target vehicle 205. A specifiedvolume for a sound can depend at least in part on a determined distanceof a target from the host vehicle 105.

FIG. 2 illustrates a traffic scene 200. A traffic scene 200 includes oneor more roads 210 and can further include one or more targets (i.e.,objects identified by the computer 110 to receive sound from the vehicle105) host vehicles and/or target vehicles 205 at any given time. Atarget vehicle 205 is a vehicle 105 such as described above for the hostvehicle 105 but referred to separately for convenience in the presentdescription. A road 210 herein, unless specified otherwise, means anyground surface designated for travel of a vehicle 105. Typically, a road210 includes a prepared travel surface, e.g., graded dirt, asphalt,gravel, etc. Further, a road 210 typically includes markings, e.g.,paint, embedded markers, etc., to guide vehicle 105 travel, e.g., in oneor more lanes. A road 210 can include more than one lane for vehicle 105travel; each lane can be designated for travel in a specified direction.In some examples, and as illustrated in FIG. 2, a first road 210 cancross or merge with a second road 210, thereby forming an intersection.

As illustrated in FIG. 2, the host vehicle 105 is moving in a forwarddirection (indicated by the arrow on the vehicle 105). Further, one ormore second vehicles 205 (referred to for convenience as “target”vehicles 205) such as the illustrated target vehicles 205 a, 205 b, 205c, 205 d, may be present in the traffic scene 200, e.g., traveling on aroad 210. Further, other objects, such as a pedestrian 215 standing atan edge of, perhaps waiting to cross, a road 210, could be present. Eachof the target vehicles 205 and/or a pedestrian 215 and/or other objectscould be stationary or moving. For example, as illustrated, thepedestrian 215 is stationary, i.e., standing in substantially a samelocation over time, and the target vehicles 205 are each moving in adirection indicated by the respective arrows on each of the illustratedtarget vehicles 205.

For present purposes, assume that the host vehicle 105 is moving awayfrom the target vehicle 205 a, i.e., the target vehicle 205 a is eitherstationary or moving in a same direction but at a slower rate of speedthan the host vehicle 105. Assume that the host vehicle 105 is movingtoward the target vehicle 205 b, i.e., the target vehicle 205 b isstationary or moving in the same direction but at a slower rate of speedand the host vehicle 105. As illustrated, the target vehicle 205 c ismoving in an opposite direction then, i.e., by convention we say has anegative speed with respect to, the host vehicle 105. Further, thetarget vehicle 205 d is moving in a direction perpendicular to that ofthe host vehicle 105. Yet further, the traffic scene 200 includes astationary pedestrian 220.

Thus, as the host vehicle 105 moves, an observer in each of the vehicles205, and the pedestrian 220, will experience sound emitted from aspeaker 135 on the vehicle 105 according to the Doppler effect. TheDoppler effect is described by Equation 1 below, in which f is observedfrequency of a wave (i.e., in present examples a sound wave) emitted ata frequency f₀, c is a speed of the wave, Δv is a difference in speedsof a wave source and wave receiver given by Δv=−(v_(r)−v_(s)), i.e., thenegative of the difference between a velocity of a wave receiver minus avelocity of a wave source.

$\begin{matrix}{f = {\left( {1 + \frac{\Delta v}{c}} \right)f_{0}}} & \left( {{Eq}.1} \right)\end{matrix}$

Note that the speed difference Δv in this simple case could be directlymeasured using a radar sensor 120A in the host vehicle 105 to measurerelative speed between the source and receiver. Further, it is to beunderstood that implementations are possible in which the source andreceiver objects are traveling with headings that are at a non-zeroangle (or not at a one-hundred-eighty degree angle) relative to eachother. That is, techniques for determining the Doppler effect whererelative velocities are radial or angular are known. In such examples Δvcan represent the relative velocity between the objects with headingsthat are at angles with respect to each other. The source velocity v_(s)may be determined using a host vehicle speed sensor, and the receivervelocity v_(r) may be determined using one or more sensors such asradar, camera, lidar, etc.

Then, if f_(r) is a frequency of a sound wave desired to be observed,i.e., received and perceived, at a target vehicle 205, c is a speed ofsound, e.g., about 343 meters per second (m/s) in air at 20° C. at sealevel), and Δv gives a difference in velocity between the host vehicle105 and a selected target vehicle 205, then Equation 2 can be used todetermine a frequency f_(t) at which a sound such as a siren soundshould be emitted to be received by the selected target vehicle 205.Note that, in Equation 2, Δv=(v_(r)−v_(s)), i.e., the difference (ratherthan the negative of the difference) between a velocity of a wavereceiver minus a velocity of a wave source (or transmitter).

$\begin{matrix}{f_{t} = {\left( {1 + \frac{\Delta v}{c}} \right)f_{r}}} & \left( {{Eq}.2} \right)\end{matrix}$

Using Equation 2, a computer 110 can, given a frequency of sound to beprovided to a receiver, determine a transmission, i.e., emission,frequency. For example, assume that it is desired that a siren sound bereceived (e.g., for perception, i.e., hearing, by someone in a targetvehicle 205) at a frequency of 800 hertz (Hz). Then, setting f_(r) to800 Hz, and assuming that a host vehicle 105 is traveling at 30 m/s anda target vehicle 205 is determined to be traveling at 20 m/s, so Δv=−10m/s, then according to Equation 2:

$f_{t} = {{\left( {1 + \frac{\Delta v}{c}} \right)f_{r}} = {{\left( {1 + \frac{{- 1}0m/s}{343m/s}} \right)800{Hz}} = {776.7{{Hz}.}}}}$

Further, because sirens and the like often transmit over a range offrequencies over time, i.e., moving from a lower frequency to a higherfrequency and back again in repetition, Equation 2 could be used todetermine upper and lower bounds for a range of frequencies fortransmission of a sound such as a siren via speakers 135. For example,800 Hz could be specified for a low end of a frequency range, and 1000Hz could be selected for a high-end of a frequency range. In that case,assuming vehicle 105, 205 speeds are determined by the computer 110 tobe 30 m/s and 20 m/s, respectively, then Equation 2 could be used todetermine a lower transmission frequency bound of 776.7 Hz, and an uppertransmission frequency bound of 970.8 Hz.

Yet further alternatively or additionally, the computer 110 could beprogrammed to transmit sound at different frequencies based on alocation of a target, e.g., depending on a presence of target vehicles205 in respective areas or zones 220 a, 220, 220 c, 220 d, 220 e(collectively referred to as zones 220) around the host vehicle 105. Forexample, the computer 110 could be programmed to define a first zone 220a to a rear of the vehicle 105. Further, the computer 110 could beprogrammed to define various zones 220 around the vehicle 105. Forexample, zones 220 can be defined with respect to an axis defined withrespect to the vehicle 105, such as the longitudinal axis 225, and lines230 at a specified angle to the axis 225 or to each other.

Note that FIG. 2 is intended to be illustrative but not limiting; onezone 220 a is shown to the rear of the host vehicle 105, and zones 220b-220 e are shown alongside and/or forward of the host vehicle 105, butthat any suitable number of zones 220 could be defined (or omitted) tothe rear or forward of the vehicle 105, or, although not shown at all inFIG. 2, two sides of the vehicle 105. Further, angles of lines 230 tothe axis 225 can be defined to so that a target located in a zone 220thus defined can have a specified location with respect to the vehicle105, e.g., forward (as with the vehicle 205 b in the zone 220 b) or tothe rear (as with the vehicle 205 a in the zone 220 a).

Yet further, in the present illustration, zones 220 are substantiallytriangular, i.e., having sides defined by lines 230 and a side furthestfrom the vehicle 105 (not shown) defined by a range of sensors 120,e.g., radar sensors 120A. However, a zone 220 could have some othershape, e.g., rectangles defined directly and/or indirectly behind andforward of the vehicle 105, etc. In general, zones 220 are defined sothat targets located in a zone 220 can be provided with sound at afrequency determined at least in part for a location within the zone220.

Continuing with the example of FIG. 2, the computer 110 could beprogrammed to select respective sound transmission frequencies forrespective zones 220 so that a received frequency of sound at a targetobject in a zone 220 will be a desired frequency accounting for theDoppler effect. For example, assume that a desired perceived frequencyof sound is 900 Hz. Further assume that a host vehicle 105 is travelingat a speed of 30 m/s, a vehicle 205 a in a zone 220 a is traveling at aspeed or velocity of 25 m/s, a vehicle 205 b in a zone 220 b istraveling at a speed of 20 m/s, and a vehicle 205 c is traveling at aspeed of −20 m/s (i.e., is traveling at a speed of 20 m/s in an oppositedirection of a direction of travel of the host vehicle 105). In thisexample, implementing Equation 2, the computer 110 could selectrespective transmission frequencies of 913.2 Hz for the zone 220 a,873.8 Hz for the zone 220 b, and 1031 Hz for the zone 220 c.

Yet further additionally or alternatively, the computer 110 could beprogrammed to select a volume, i.e., amplitude of a sound wave, or soundtransmitted within a specified zone 220. For example, a louder volume(e.g., 100 decibels) could be selected for a forward zone 220 b, and aless loud volume (e.g., 75 decibels) could be selected for a rear zone220 a. Yet further, the computer 110 could be programmed to select avolume and/or a frequency of sound based on a distance of a target fromthe vehicle 105 and/or according to a specified zone 220 and/oraccording to a type of target. For example, the computer 110 could beprogrammed to increase a volume of sound, e.g., from 75 decibels to 100decibels, upon detecting a target within a specified distance, e.g., 25meters, of the host vehicle 105, possibly also upon detecting that thetarget is stopped or moving more than a specified speed difference fromthe host vehicle 105, each, more than 50 percent slower. Yet furtheradditionally or alternatively, the computer 110 could be programmed toincrease a volume of sound, e.g., from 50 decibels to 100 decibels, atleast in part based on a type of target, e.g., based on a pedestrian 215in a forward zone 220 b, 220 c, 22 e.

FIG. 2 further illustrates a target vehicle 205 d in a zone 220 d. Thetarget vehicle 205 d is traveling in a direction substantiallyperpendicular to a direction of travel of the host vehicle 105.

FIG. 3 is a flow diagram of an exemplary process 300 for controllingsound emitted from a vehicle 105. The process 300 begins in a block 305,in which the computer 110 in the vehicle 105 receives input to emit asound, e.g., a siren. For example, input can be provided via an HMI 115,e.g., by selecting a button or virtual button, etc. Typically thecomputer 110 will store a frequency or range of frequencies of sounddesired to be received by an observer, e.g., a frequency or frequencyconventionally used for an emergency vehicle siren. However, a usercould alternatively or additionally provide input specifying a frequencyor range of frequencies of sound desired to be received by an observer,e.g., overriding a default value or values stored by the computer 110.

Next, in a block 310, the computer 110 can determine a speed of the hostvehicle 105, e.g., via a speed sensor 120B such as discussed above.

Next, in a block 315, the computer 110 can determine whether the hostvehicle 105 speed is substantially greater than zero (e.g., fivekilometers per hour or more), i.e., whether the host vehicle 105 ismoving in a forward direction. The block 315 could be omitted, but istypically it is useful to adjust a frequency of emitted sound(s) fromspeakers 135 only if the vehicle 105 is in motion. If the vehicle 105 ismoving forward, then a block 320 is executed next. If not, a block 330is executed next.

In the block 320, the computer 110, e.g., using various techniques forinterpreting data from sensors 120, e.g., data from a radar sensor 120A,determines whether one or more targets, e.g., target vehicles 205 and/orpedestrians 215, are present within a range of applicable sensors 120.For example, one or more radar sensors 120A, cameras, lidar, etc., couldbe used to detect a presence of target vehicles 205. If one or moretargets are detected, then a block 325 is executed next. Otherwise, theprocess 300 proceeds to the block 330.

In the block 325, the computer 110 determines a value Δv as discussedabove for each of the one or more detected target vehicles 205 and/orother targets, such as one or more pedestrians 215. That is, thecomputer 110 determine a difference between a host vehicle 105 speed,e.g., as detected by a vehicle 105 speed sensor 120B, and a respectivetarget, e.g., target vehicle 205 speed, e.g., as detected by a radarsensor 120A, to determine the value Δv for that target vehicle 205.

Next, in a block 330, the computer 110 determines one or more respectivesound transmission frequencies, and possibly also specifies a volume,for emitting a sound or sounds from speaker(s) 135, and/or a time ortimes for emitting a sound or sounds at a specified frequency orfrequencies (see the transmission pattern discussed further below withrespect to FIG. 4). When the block 330 is reached following one of theblocks 315, 320, the computer 110 typically is programmed to select adefault value or values, e.g., a specified frequency or range offrequencies predetermined for situations where the vehicle 105 is notmoving and/or where no target is present, then proceed to a block 335.However, if the vehicle 105 is moving and one or more targets have beenidentified, then the computer 110 can implement Equation 2 to determinea transmission frequency based on a relative velocity of a targetvehicle 205, and/or could determine a range of frequencies based on arelative velocity of a target vehicle 205, and moreover could determinerespective transmission frequencies or ranges of transmissionfrequencies for respective target vehicles 205. A process 400 that couldbe executed within the block 330 to determine a frequency orfrequencies, and to specify zones 220 for respective frequencies to betransmitted, as described further below with respect to FIG. 4.

Following the block 330, in a block 335, the computer 110 actuates thefrequency generator 130 and speaker 135 to emit the sound as specifiedin the block 330, e.g., according to a transmission pattern as discussedbelow with respect to the process 400.

Next, in the block 340, the computer 110 determines whether the process300 is to continue. For example, input could be received at the HMI 115to terminate the emission of sound from the vehicle 105. If the process300 is to continue, the computer 110 next executes the block 310.Otherwise, the process 300 ends.

FIG. 4 illustrates an example process 400 to determine a frequency orfrequencies, and to specify zones 220 for respective frequencies to betransmitted, from a host vehicle 105.

The process 400 begins in a block 405, in which the computer 110identifies one or more zones 220 occupied by a target such as a targetvehicle 205 or pedestrian 215. Zones 220 could be predetermined andstored in a memory of the computer 110, e.g., defined by lines 230 at aspecified angle or angles to an axis 225 of the vehicle 105. Thecomputer 110 could then identify zero, one, or more targets inrespective zones 220, i.e., by interpreting data from one or moresensors 120 indicating a target or targets, or lack thereof, in a zone220.

Next, in a block 410, the computer 110 selects a transmission frequencyor range of frequencies for each zone 220 identified in the block 405.For example, the computer 110 could select a target such as a targetvehicle 205 or pedestrian 215 in each zone 220, and could use a detectedspeed of the selected target along with a current speed of the hostvehicle 105 in Equation 2 to determine the selected transmissionfrequency or range of frequencies for a zone 220. If more than onetarget is present in a zone, the target could be selected based on aprioritization rule or rules stored by the computer 110. For example, apedestrian 215 could be given priority over a vehicle 205. In anotherexample, a closest target, e.g., a closest vehicle 205 to the hostvehicle 105 in a zone 220 could be the selected target in that zone 220.In yet another example, multiple targets in a zone 220, e.g., alltargets within a specified distance of the host vehicle 105, e.g., 100meters or 200 meters, etc., could be selected, and the speeds of thesetargets could be averaged and used in Equation 2.

Next, in a block 415, the computer 110 specifies a transmission patternfor sound to be emitted from one or more speakers 135 on the vehicle105. A transmission pattern in the present context means a specificationof a time or times for emitting sound at a specified frequency, andpossibly also a direction or directions, e.g., directions whereby soundis emitted in or toward a selected zone 220, for emitting sound at thetime or times. A direction could be specified with respect to a vehicle105, e.g., as an angle with respect to a longitudinal axis 225. Asillustrated in FIG. 2, a vehicle 105 can include multiple speakers 135,e.g., different speakers 135 could be oriented in various directions toemit sound toward zones 220 around the vehicle 105. Alternatively, avehicle 105 could include a single speaker 135; a speaker (or speakers)135 could be arranged to utilize any suitable mechanism fordirectionally transmitting sound, i.e. to transmit sound in a specifieddirection. In any event, whether the vehicle 105 includes one or morespeakers 135, a speaker 135 could be configured to physically rotateand/or to directionally emit sound.

A transmission pattern could specify, for example, to emit sound at afirst frequency or range of frequencies toward a first zone 220, and toemit sound at a second frequency or second range of frequencies toward asecond zone 220. In one example, the transmission pattern could specifyto emit sound toward the first and second zones 220 for a same amount,and/or same periods, of time. In another example, the transmissionpattern can specify different amounts of time for emitting sound towardrespective zones. For example, the computer 110 could identify a firstzone 220 as having a higher priority than a second zone 220, e.g.,referring back to FIG. 2, the zone 220 b could have a highest priorityover all other zones 220 because it is forward of and in the path of thevehicle 105. The zone 220 c could have a next highest priority, becausethe vehicle 105 is moving closer to targets in that zone, and paths ofthe vehicle 105 and targets in the zone 220 c could be at a higher riskof intersecting than paths of targets in other zones 220 (besides theforward zone 220 b). Yet further, the zone 220 a could have athird-highest priority because targets in that zone are in a same laneand/or moving on a same direction of travel as the host vehicle 105.Accordingly, a transmission pattern could specify emitting sound in adirection of a first zone 220 a for a first amount of time at afrequency or frequencies specified for that zone 220 a, e.g., fourseconds, and then to emit sound for a second amount of time toward asecond zone 220 b, e.g., two seconds, at a second frequency orfrequencies specified for the second zone 220 b, etc.

A transmission pattern can also specify a frequency and/or a volumeaccording to a location of a host vehicle 105, a type of target and/or adistance of a target from a host vehicle 105. For example, in certaincircumstances, it may be desirable for an emergency vehicle 105 to emitwhat is sometimes referred to as a chirping sound, e.g., when a vehicle205 is slowed or stopped in front of the emergency vehicle 105, when theemergency vehicle 105 is approaching are traveling through intersection,etc. Accordingly, the computer 110 could be programmed to specify atransmission pattern including a mission of short (e.g., one second orless) first of sound at a higher frequency than a frequency specifiedfor a siren, and at a higher volume. The transmission pattern couldspecify the short bursts or chirps on one or more of the followingconditions: the vehicle 105 is in or within a predetermined distance(e.g., 50 meters) of intersection, the vehicle 105 is within apredetermined distance of a specified type of target, e.g., a pedestrian215, and/or the vehicle 105 is within a predetermined distance (e.g., 30meters) of a target vehicle 205 that is stopped or slowed, G, moving atmore than a predetermined amount (e.g., 50 percent) slower than the hostvehicle 105. Further, a volume of future or short burst of sound couldbe specified according to a distance from a target, e.g., 120 decibelsat a range of 100 meters, 100 decibels at a range of 50 meters, and 60decibels at a range of 20 meters.

Following the block 415, the process 400 ends.

As used herein, the adverb “substantially” means that a shape,structure, measurement, quantity, time, etc. may deviate from an exactdescribed geometry, distance, measurement, quantity, time, etc., becauseof imperfections in materials, machining, manufacturing, transmission ofdata, computational speed, etc.

In general, the computing systems and/or devices described may employany of a number of computer operating systems, including, but by nomeans limited to, versions and/or varieties of the Ford Sync®application, AppLink/Smart Device Link middleware, the MicrosoftAutomotive® operating system, the Microsoft Windows® operating system,the Unix operating system (e.g., the Solaris® operating systemdistributed by Oracle Corporation of Redwood Shores, Calif.), the AIXUNIX operating system distributed by International Business Machines ofArmonk, N.Y., the Linux operating system, the Mac OSX and iOS operatingsystems distributed by Apple Inc. of Cupertino, Calif., the BlackBerryOS distributed by Blackberry, Ltd. of Waterloo, Canada, and the Androidoperating system developed by Google, Inc. and the Open HandsetAlliance, or the QNX® CAR Platform for Infotainment offered by QNXSoftware Systems. Examples of computing devices include, withoutlimitation, an on board first computer, a computer workstation, aserver, a desktop, notebook, laptop, or handheld computer, or some othercomputing system and/or device.

Computers and computing devices generally include computer executableinstructions, where the instructions may be executable by one or morecomputing devices such as those listed above. Computer executableinstructions may be compiled or interpreted from computer programscreated using a variety of programming languages and/or technologies,including, without limitation, and either alone or in combination,Java™, C, C++, Matlab, Simulink, Stateflow, Visual Basic, Java Script,Perl, HTML, etc. Some of these applications may be compiled and executedon a virtual machine, such as the Java Virtual Machine, the Dalvikvirtual machine, or the like. In general, a processor (e.g., amicroprocessor) receives instructions, e.g., from a memory, a computerreadable medium, etc., and executes these instructions, therebyperforming one or more processes, including one or more of the processesdescribed herein. Such instructions and other data may be stored andtransmitted using a variety of computer readable media. A file in acomputing device is generally a collection of data stored on a computerreadable medium, such as a storage medium, a random access memory, etc.

Memory may include a computer readable medium (also referred to as aprocessor readable medium) that includes any non transitory (e.g.,tangible) medium that participates in providing data (e.g.,instructions) that may be read by a computer (e.g., by a processor of acomputer). Such a medium may take many forms, including, but not limitedto, non volatile media and volatile media. Non volatile media mayinclude, for example, optical or magnetic disks and other persistentmemory. Volatile media may include, for example, dynamic random accessmemory (DRAM), which typically constitutes a main memory. Suchinstructions may be transmitted by one or more transmission media,including coaxial cables, copper wire and fiber optics, including thewires that comprise a system bus coupled to a processor of an ECU.Common forms of computer readable media include, for example, a floppydisk, a flexible disk, hard disk, magnetic tape, any other magneticmedium, a CD ROM, DVD, any other optical medium, punch cards, papertape, any other physical medium with patterns of holes, a RAM, a PROM,an EPROM, a FLASH EEPROM, any other memory chip or cartridge, or anyother medium from which a computer can read.

Databases, data repositories or other data stores described herein mayinclude various kinds of mechanisms for storing, accessing, andretrieving various kinds of data, including a hierarchical database, aset of files in a file system, an application database in a proprietaryformat, a relational database management system (RDBMS), etc. Each suchdata store is generally included within a computing device employing acomputer operating system such as one of those mentioned above, and areaccessed via a network in any one or more of a variety of manners. Afile system may be accessible from a computer operating system, and mayinclude files stored in various formats. An RDBMS generally employs theStructured Query Language (SQL) in addition to a language for creating,storing, editing, and executing stored procedures, such as the PL/SQLlanguage mentioned above.

In some examples, system elements may be implemented as computerreadable instructions (e.g., software) on one or more computing devices(e.g., servers, personal computers, etc.), stored on computer readablemedia associated therewith (e.g., disks, memories, etc.). A computerprogram product may comprise such instructions stored on computerreadable media for carrying out the functions described herein.

With regard to the media, processes, systems, methods, heuristics, etc.described herein, it should be understood that, although the steps ofsuch processes, etc. have been described as occurring according to acertain ordered sequence, such processes may be practiced with thedescribed steps performed in an order other than the order describedherein. It further should be understood that certain steps may beperformed simultaneously, that other steps may be added, or that certainsteps described herein may be omitted. In other words, the descriptionsof processes herein are provided for the purpose of illustrating certainembodiments and should in no way be construed so as to limit the claims.

Accordingly, it is to be understood that the above description isintended to be illustrative and not restrictive. Many embodiments andapplications other than the examples provided would be apparent to thoseof skill in the art upon reading the above description. The scope of theinvention should be determined, not with reference to the abovedescription, but should instead be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled. It is anticipated and intended that futuredevelopments will occur in the arts discussed herein, and that thedisclosed systems and methods will be incorporated into such futureembodiments. In sum, it should be understood that the invention iscapable of modification and variation and is limited only by thefollowing claims.

All terms used in the claims are intended to be given their plain andordinary meanings as understood by those skilled in the art unless anexplicit indication to the contrary in made herein. In particular, useof the singular articles such as “a,” “the,” “said,” etc. should be readto recite one or more of the indicated elements unless a claim recitesan explicit limitation to the contrary.

The invention claimed is:
 1. A system for a host vehicle, comprising: anobject detection sensor; a frequency generator coupled to a speaker; anda computer that includes a processor and a memory, the memory storinginstructions executable by the processor such that the processor isprogrammed to: based on data from the object detection sensor, identifytargets in respective zones around the host vehicle; identify amulti-target zone from the plurality of zones that includes two or moreof the targets; select a target to represent the multi-target zone basedon prioritizing the two or more targets within the multi-target zone;detect respective speeds of the targets relative to the host vehiclebased on data from the object detection sensor; specify respectivetarget frequencies for a sounds to be received at the targets vehicle;determine respective sending frequencies for the sounds based on thetarget frequencies and the respective relative speeds of the targets;and transmit the sounds according to a transmission pattern thatspecifies the sending frequencies and respective times for sending thesounds.
 2. A system comprising a computer for a host vehicle thatincludes a processor and a memory, the memory storing instructionsexecutable by the processor such that the processor is programmed to:identify targets in respective zones around the host vehicle; identify amulti-target zone from the plurality of zones that includes two or moreof the targets; select a target to represent the multi-target zone basedon prioritizing the two or more targets within the multi-target zone;detect respective speeds of the targets; determine differences in aspeed of the host vehicle and the speeds of the targets vehicle; specifyrespective target frequencies for sounds to be received at the targets;determine respective sending frequencies for the sounds based on thetarget frequencies and the difference in host vehicle speed and targetspeeds; and transmit the sounds according to a transmission pattern thatspecifies the sending frequencies and respective times for sending thesounds.
 3. The system of claim 2, wherein the instructions furtherinclude instructions to actuate a first speaker to transmit a first oneof the sounds at a first one of the sending frequencies and a secondspeaker to transmit a second one of the sounds at a second one of thesending frequencies.
 4. The system of claim 2, wherein the instructionsfurther include instructions to actuate a speaker at a first time totransmit a first one of the sounds at a first one of the sendingfrequencies and to actuate the speaker at a second time to transmit asecond one of the sounds at a second one of the sending frequencies. 5.The system of claim 2, the instructions further including instructionsto: specify a range of frequencies for one of the sending frequencies;and transmit one of the sounds within the range of frequencies.
 6. Thesystem of claim 2, wherein the speed of the host vehicle is determinedvia a host vehicle speed sensor.
 7. The system of claim 2, wherein thespeed of at least one of the targets is detected via a host vehicleradar.
 8. The system of claim 2, the instructions further comprisinginstructions to determine to transmit a second sound based on a distanceof one of the targets.
 9. The system of claim 8, the instructionsfurther comprising instructions to transmit the second sound at a volumebased on the distance of the of one of the targets.
 10. The system ofclaim 2, the instructions further comprising instructions to identifythe targets based on respective locations of the targets.
 11. The systemof claim 2, the instructions further comprising instructions to specifythe sending frequencies for the sounds based at least in part on alocations of the targets.
 12. The system of claim 2, the instructionsfurther comprising instructions to specify the target frequencies basedat least in part on respective locations of the targets relative to thehost vehicle.
 13. A method, comprising: identifying targets inrespective zones around the host vehicle; identifying a multi-targetzone from the plurality of zones that includes two or more of thetargets; selecting a target to represent the multi-target zone based onprioritizing the two or more targets within the multi-target zone;detecting respective speeds of the targets; determining differences in aspeed of the host vehicle and the speeds of the targets; specifyingrespective target frequencies for sounds to be received at the targets;determining respective sending frequencies for the sounds based on thetarget frequencies and the difference in host vehicle speed and targetspeeds; and transmitting the sounds according to a transmission patternthat specifies the sending frequencies and respective times for sendingthe sounds.
 14. The method of claim 13, further comprising: specifying arange of frequencies for one of the sending frequencies; andtransmitting one of the sounds within the range of frequencies.
 15. Themethod of claim 13, wherein the speed of the host vehicle is determinedvia a host vehicle speed sensor.
 16. The method of claim 13, wherein thespeed of at least one of the targets is detected via a host vehicleradar.
 17. The method of claim 13, further comprising identifying thetargets based on respective locations of the targets.
 18. The method ofclaim 13, further comprising specifying the target frequencies based atleast in part on respective locations of the targets relative to thehost vehicle.